Transmitting antennas have many purposes ranging from simple communication from one point to another to the tracking of objects (e.g., vehicles, ships, aircraft) to the jamming of remote communication systems. The power, frequency, and polarization of the signals transmitted depend on the particular application and the antenna configuration. For example, jamming involves the transmission of high power random signals to impair an unfriendly radar's operation (e.g., by saturating its receiver or obscuring target echoes on its display). The disruptive jamming signals are through the entire frequency band used by the unfriendly radar.
A conventional jammer configuration includes a broadband dual polarized diagonal horn that covers an entire frequency band of interest, and two full band transmitters space combined to produce vertical, horizontal, or circular polarization. The phase shift to control the particular polarization is performed by the backend circuit of the antenna system, as is known.
One problem associated with such dual polarized antennas is that they typically require a dual channel rotary joint to provide continuous rotating performance. Dual channel rotary joints are physically large. In addition, they typically have a shunt stub in one channel that limits the low VSWR bandwidth and power, and also prohibits phase tracking.
What is needed, therefore, is a high power positional fixture configuration for a multi-polarized antenna.